Organ Systems A quick bite to eat! How many systems are involved in eating?

The Digestive System How much do you already know? Use props to assemble a digestive system

How much do you already know? A – Mouth B – Esophagus C – Stomach D – Small intestine E – Large intestine

The function of the digestive system: the physical and chemical breakdown of food into smaller nutrient molecules that can be absorbed from the digestive tract

The Digestive Tract In most animals, the digestive tract is one long tube with openings at either end

The Whole Digestive Tract lined with epithelial tissue containing goblet cells that produce mucous Epithelial tissue with goblet cells Connective tissue Muscle tissue Epithelial tissue

The Whole Digestive Tract Mucous helps 1) protects digestive tract from digestive enzymes 2) Lubricate for smooth passage of materials Epithelial tissue with goblet cells Connective tissue Muscle tissue Epithelial tissue

1. Digestion – The mouth Mouth: food is chewed and swallowed. Causes mechanical (physical) breakdown of food.

1. Digestion – The mouth Enzymes, (from the salivary glands), start the chemical breakdown of starch and other sugars into simpler compounds. Amylase: the enzyme in the mouth that helps us break down starch and complex carbohydrates

2. Digestion - The Esophagus Passageway that moves food to the stomach by peristalsis

2. Digestion - The Esophagus Peristalsis – wave-like contractions of the smooth (involuntary) muscles

3. Digestion – The Stomach Smooth Muscle tissue allows churning of the food for further physical and chemical breakdown of food

3. Digestion – The stomach Epithelial tissue in lining secretes enzymes and acids for chemical breakdown of food Epithelial tissue and enzyme producing cells

4. Digestion – The Small Intestine More digestive juices added to further break down food into smaller nutrients

4. Digestion – The Small Intestine Villi -(Finger-like projections) increase the surface area of the small intestine lining.

4. Digestion – The Small Intestine Small nutrient molecules are absorbed by the villi into the blood stream

5. Digestion – Large Intestine Water from food is reabsorbed into the body for recycling Solidified indigestible waste is pushed through and expelled

Accessory Organs The gall bladder, liver & pancreas supply digestive tract with further enzymes and bile to aid chemical breakdown.

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The Circulatory System Functions as a “courier system” Delivers to body cells nutrients and oxygen (O 2 ) Picks up for disposal carbon dioxide (CO 2 ) and other wastes

Circulatory System Is made up of 3 main parts: - The Blood - The Heart - The Blood Vessels

StructureFunction Red Blood Cells Contain hemoglobin Carry oxygen White Blood Cells Contain a nucleus Destroy bacteria and viruses PlateletsTiny pieces of cells Help with blood clotting PlasmaProtein rich liquid Fluid enables blood flow COMPONENTS OF BLOOD

The Heart - Contains cardiac muscle tissue allowing each part of the heart to contract simultaneously

The Heart The heart must pumps at a regular beat in order to carry blood to all body tissues. The heart rate varies depending on: physical activity stress temperature general health.

Three types of Blood Vessels Arteries – carry blood away from the heart. Thick walls to withstand higher blood pressure Contain oxygen-rich blood

Three types of Blood Vessels Veins – carry blood towards the heart. Thin walls (further from heart - lower blood pressure)

Three types of Blood Vessels Capillaries – tiny vessels within all body tissues Thin walls allow diffusion for exchange of substances with body tissue.

The Heart- pathway of blood flow through the heart Deoxygenated blood from rest of body to right atrium via superior and inferior vena cava  right atrium  right ventricle  pulmonary artery  lung where blood picks up O 2  left atrium via pulmonary veins  left ventricle  oxygenated blood left heart via aorta to rest of the body Blood from upper body Blood from lower body 

This colour-enhanced, freeze-fracture scanning electron micrograph shows a blood vessel that has grown into a melanoma. Numerous red blood cells and three white blood cells can be seen within the blood vessel.

The End

Reserved for next class

Try it yourself 1. Label A  D in the diagram below. 2. Which kind of blood (deoxygenated/oxygenated?) that entering: a. superior vena cava b. pulmonary vein c. pulmonary artery d. aorta 3. Where does the blood come from before entering the superior vena cava? 4. Where does the blood come from before entering the inferior vena cava? 5. Where does the blood go to after leaving the pulmonary artery? 6. The part receives blood from lung is: a.left ventriclec. left atrium b.right atriumd. right atrium